We are requesting funds to purchase high throughput automation for the in vitro selection and characterization of recombinant antibodies. The antibodies will be displayed on phage or yeast, and selected against antigens that are either purified or displayed on eukaryotic cells. These antibodies will serve as biological probes, biomarkers and potential therapeutics. There is currently no appropriate instrumentation for this technology at UCSF or nearby campuses. The addition of this high-throughput automation would therefore serve a unique purpose at UCSF, while supporting at least five NIH-funded projects. The new equipment would be placed in the Small Molecule Discovery Center (SMDC) at UCSF and be available to the entire UC community. The SMDC has already established the space, staff, and recharge policies to maintain this equipment. The SMDC includes a high-throughput screening (HTS) group and is therefore well-positioned to maximize the use of new automation for technology development. Antibodies are essential reagents for determining how proteins function under normal or pathophysiological conditions. Uses of antibodies include quantifying proteins, identifying the temporal and spatial pattern of expression in cells and tissue, and identifying interacting partners. Such studies require antibodies of high specificity that function in assays including Western blotting, immunoprecipitation, immunohistochemistry (IHC) and in vivo imaging. Over half the human proteome is not annotated and functional antibodies are not reliably available for these proteins. Many of the limitations of traditional antibody generation can be overcome by the use of display technologies and antibody (Ab) gene diversity libraries. The purchase of this instrument has broad support from three major users with well-established research programs from three departments at two different UCSF campuses. The automation would support the NIH funded research of these users and future minor users throughout UCSF.